Imaging of vascular inflammation with [11C]-PK11195 and positron emission tomography/computed tomography angiography
Journal of the American College of Cardiology. 2010-08-01; 56(8): 653-661
DOI: 10.1016/j.jacc.2010.02.063
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1. J Am Coll Cardiol. 2010 Aug 17;56(8):653-61. doi: 10.1016/j.jacc.2010.02.063.
Imaging of vascular inflammation with [11C]-PK11195 and positron emission
tomography/computed tomography angiography.
Pugliese F(1), Gaemperli O, Kinderlerer AR, Lamare F, Shalhoub J, Davies AH,
Rimoldi OE, Mason JC, Camici PG.
Author information:
(1)Medical Research Council Clinical Sciences Centre and National Heart and Lung
Institute, Imperial College, and Hammersmith Hospital, London, United Kingdom.
OBJECTIVES: We sought to investigate whether positron emission
tomography/computed tomography (CT) angiography using [11C]-PK11195, a selective
ligand for peripheral benzodiazepine receptors expressed in activated
macrophages, can be used to image vascular inflammation.
BACKGROUND: Activated macrophages and T lymphocytes are fundamental elements in
the pathogenesis of large-vessel vasculitides.
METHODS: Fifteen patients (age 52+/-16 years) with systemic inflammatory
disorders (6 consecutive symptomatic patients with clinical suspicion of active
vasculitis and 9 asymptomatic control patients) underwent positron emission
tomography with [11C]-PK11195 and CT angiography. [11C]-PK11195 uptake was
measured by calculating target-to-background ratios of activity normalized to
venous blood.
RESULTS: Coregistration of positron emission tomography with contrast-enhanced CT
angiography facilitated localization of [11C]-PK11195 arterial wall uptake.
Visual analysis revealed focal [11C]-PK11195 uptake in the arterial wall of all 6
symptomatic patients, but in none of the asymptomatic controls. Although serum
inflammatory biomarkers (C-reactive protein, erythrocyte sedimentation rate,
white cell count) did not differ significantly between the 2 groups, symptomatic
patients had increased [11C]-PK11195 vascular uptake (target-to-background ratio
2.41+/-1.59 vs. 0.98+/-0.10; p=0.001).
CONCLUSIONS: By binding to activated macrophages in the vessel wall,
[11C]-PK11195 enables noninvasive imaging of vascular inflammation. Alternative
longer-lived radioligands for probing peripheral benzodiazepine receptors are
being tested for wider clinical applications.
Copyright (c) 2010 American College of Cardiology Foundation. Published by
Elsevier Inc. All rights reserved.
DOI: 10.1016/j.jacc.2010.02.063
PMID: 20705222 [Indexed for MEDLINE]